Herb, well u did almost answer all my question. Now i have a NAT
connection to internet and my client can access through it. In NAT only
the public interface has the traffic/mapping but not the internal
nic/interface.
I just wonder how could this be ? but overall the NAT is
working.
If you are just asking how such NATs do this, I
can likely explain. (If so, this is perfectly normal....)
NATs only translate outbound traffic when sending OUT
and external (and NATed) interface.
Traffic entering on a non translated (usually Internal) interface
can exit another such interface without being translated and
then there is nothing to "remember" (or map).
The simple NATs usually only have 2 interfaces, so it is easy
to assume that this is the only case -- but even this is no longer
the common case for many such devices: I have several that
have two internal interfaces (Wireless and Ethernet) plus
another External interface (to the cable/DSL etc.).
You can communitate between Wireless and internal Ethernet
with NO mapping just like on any other router (or like a bridge
if you use this setting.)
But what u mentioned abt the Manual mapping , does it mean
like establishing multiuser game connection or static route to another
server via some preset ports ?
Yes. (usually)
does this connection establish via the
internal nic ?
this is what i want to know also. Thanks
No, it initiates on the EXTERNAL NIC, e.g.,:
Trying to Terminal serve to an internal machine:
Map External IP of NAT, on TCP port 3389, to address
of internal machine on port 3389.
You could even map a web request on external address
TCP port 80 to an internal Web server on port 8000
(or any other port the internal server can service.)
